Objective: To evaluate fecal calprotectin concentrations in healthy dogs and dogs with chronic diarrhea, to identify cutoff values for fecal calprotectin concentrations for use in differentiating dogs with chronic diarrhea and a canine chronic enteropathy clinical activity index (CCECAI) < 12 from dogs with chronic diarrhea and a CCECAI ≥ 12, and to evaluate the association between histologic evidence of intestinal mucosal changes and fecal calprotectin concentrations in dogs with chronic diarrhea. Sample: Fecal samples from 96 adult dogs (27 dogs with chronic diarrhea and 69 healthy control dogs). Procedures: Severity of clinical signs was evaluated on the basis of the CCECAI scoring system. Endoscopy was performed in all dogs with chronic diarrhea, and mucosal biopsy specimens were evaluated histologically. Fecal calprotectin concentration was quantified via radioimmunoassay. Results: Fecal calprotectin concentrations were significantly higher in dogs with chronic diarrhea than in healthy control dogs. Fecal calprotectin concentrations were also significantly higher in dogs with a CCECAI ≥ 12, compared with concentrations for dogs with a CCECAI between 4 and 11. Fecal calprotectin concentrations were significantly higher in dogs with chronic diarrhea associated with histologic lesions, compared with concentrations in control dogs, and were significantly correlated with the severity of histologic intestinal lesions. Among dogs with chronic diarrhea, the best cutoff fecal calprotectin concentration for predicting a CCECAI ≥ 12 was 48.9 μg/g (sensitivity, 53.3%; specificity, 91.7%). Conclusions and Clinical Relevance: Fecal calprotectin may be a useful biomarker in dogs with chronic diarrhea, especially dogs with histologic lesions.

Objective—To evaluate effects of quaternary benzo(c)phenanthridine alkaloids (QBAs) against Salmonella spp and determine effects on growth performance, organism shedding, and gastrointestinal tract integrity in pigs inoculated with Salmonella enterica serovar Typhimurium. Sample—36 Salmonella isolates and twenty 5-week-old pigs. Procedures—Minimum inhibitory concentration of QBAs against the Salmonella isolates was determined. Pigs were allocated to 4 groups and inoculated with Salmonella organisms. Pigs received diets supplemented with 1.5 g of QBAs/1,000 kg of feed, 0.75 g of QBAs/1,000 kg of feed, or 59.4 g of chlortetracycline/1,000 kg of feed or a nonsupplemented (control) diet. Pigs were weighed on day 0 and then weekly for 40 days. Fecal samples were collected to quantify Salmonella organisms. Gastrointestinal tract integrity was evaluated by measuring transepithelial resistance. Results—In vitro, 9 of 36 (25%) Salmonella isolates were inhibited at 90 μg of QBAs/mL; all 36 were inhibited at 179 μg of QBAs/mL. Diets containing QBAs significantly decreased Salmonella spp shedding; shedding was lower 40 days after inoculation for pigs fed diets containing QBAs or chlortetracycline than for pigs fed the control diet. Growth performance was similar for pigs fed diets containing QBA or chlortetracycline. Gastrointestinal tract integrity was improved in pigs fed the diet containing 1.5 g of QBAs/1,000 kg of feed. Conclusions and Clinical Relevance—QBAs and chlortetracycline decreased Salmonella spp shedding but did not differ with regard to growth performance. Gastrointestinal tract integrity was better, albeit not significantly, in pigs fed diets containing QBAs. Further investigation into the role of QBAs and their mechanism as an immunomodulator is necessary.

Objective-To determine the response to neostigmine of the contractile activity of the jejunum and pelvic flexure and the effects of a continuous rate infusion (CRI) of neostigmine in horses. Animals-7 adult horses and tissue from 12 adult horses. Procedures-A CRI of neostigmine (0.008 mg/kg/h) or placebo was administered to 6 horses in a crossover study design. Gastric emptying was evaluated by the acetaminophen test. The frequency of defecation and urination and the consistency and weight of feces were recorded throughout the experiment. The effect of neostigmine on smooth muscle contractile activity was evaluated in tissues from the jejunum and pelvic flexure. The effect of neostigmine and acetylcholine after incubation with muscarinic receptor antagonists (atropine and DAU 5884) and an acetylcholinesterase inhibitor (edrophonium) was also investigated in vitro. Results-No difference was observed between neostigmine and placebo for time to reach peak plasma acetaminophen concentration and absorption rate constant. A CRI of neostigmine increased fecal production and frequency of urination. Neostigmine induced a dose-dependent increase of contractile amplitude in jejunum and pelvic flexure muscle strips. Incubation of muscle strips with atropine and DAU 5884 inhibited the response to acetylcholine and neostigmine. Incubation of smooth muscle strips from the jejunum with edrophonium increased the response to acetylcholine and had no effect on the response to neostigmine in vitro. Conclusions and Clinical Relevance-A CRI of neostigmine increased fecal production and urination frequency in horses. A CRI of neostigmine did not decrease gastric emptying. Neostigmine stimulated contractile activity of jejunum and pelvic flexure smooth muscle strips in vitro.

We evaluated the immunogenic and protective potential of a recombinant VapA/CpG oligodeoxynucleotide (ODN) 2395 vaccine in neonatal foals undergoing experimental Rhodococcus equi challenge. Foals (n = 8) were vaccinated by intramuscular injection on days 1 and 15 of the study; control foals (n = 7) received a phosphate-buffered saline (PBS) solution. All foals were challenged by intrabronchial administration of 5 × 106R. equi 103+ on day 29. Bronchoalveolar lavages were done on days 15, 29, and 36 and total cell count, differential cell count, rVapA-stimulated cell proliferation and interferon (IFN)-γ mRNA expression determined. Clinical examination, complete blood (cell) counts, serology for VapA-specific antibodies, and culture of nasal and fecal swabs were done on days 1, 15, 29, 36, 43, and 50. Foals were humanely euthanized on day 50 and severity of pneumonia scored on a 4-point scale. Vaccination resulted in a significant increase in VapA-specific immunoglobulin (Ig) production, with total IgG and IgG(T) being increased by day 15. Expression of VapA-specific IFN-γ mRNA by BAL cells was increased in the vaccinated foals following challenge. Postmortem lung severity scores did not differ between groups. Two foals shed virulent R. equi in feces; however, real-time polymerase chain reaction (PCR) revealed the isolates to be different from the challenge strain.

Objective-To determine the effects of domperidone on in vivo and in vitro measures of gastrointestinal tract motility and contractility in healthy horses. Sample-18 adult horses and tissue samples from an additional 26 adult horses. Procedures-Domperidone or placebo paste was administered to healthy horses in a 2-period crossover study. Gastric emptying was evaluated after oral administration of domperidone paste (1.1 or 5.0 mg/kg) or placebo paste by means of the acetaminophen absorption test in 12 horses. Frequency of defecation, weight of feces produced, fecal moisture, and stomach-to-anus transit time of microspheres were evaluated after administration of domperidone paste (1.1 mg/kg) or placebo paste in 6 horses. The effect of domperidone on smooth muscle contractile activity in samples of duodenum, jejunum, ileum, or colon obtained from 26 horses immediately after euthanasia (for nonsystemic medical problems) was investigated. Results-Oral administration of 5.0 mg of domperidone/kg increased peak plasma acetaminophen concentration and area under the curve, indicating increased gastric emptying. Administration of 1.1 mg of domperidone/kg had no effect on gastric emptying, transit time, defecation frequency, or amount and moisture of excreted feces. Contractile activities of circular and longitudinal muscle strips from the duodenum, jejunum, ileum, or colon were not altered by domperidone. Dopamine increased contractile activity of longitudinal muscle strips but not that of circular muscle strips from the midjejunum. Domperidone decreased the dopamine-induced contractile activity of midjejunal longitudinal muscle strips. Conclusions and Clinical Relevance-The potential beneficial effects of domperidone in horses with ileus need to be evaluated in horses with decreased gastric emptying or adynamic ileus.

Objective—To evaluate the effect of delayed exposure of dairy cattle to Mycobacterium avium subsp paratuberculosis (MAP) on the incidence of those cows testing positive for MAP and developing clinical Johne's disease (CJD). Animals—79 cows not exposed to MAP as calves (unexposed cohort) and 260 cows exposed to MAP as calves (exposed cohort). Procedures—Cows in the unexposed cohort were born into 5 MAP-uninfected herds and introduced at various ages into 5 MAP-infected herds where the exposed cohort cows were born and raised. Beginning when each cow was 24 months old, fecal and serum samples were collected annually from 2003 through 2006. Feces were cultured for MAP, and an ELISA was used to analyze serum samples for antibodies against MAP. Date and reason for culling were obtained from herd records. Incidence of positive culture and ELISA results and CJD was compared between unexposed and exposed cohort cows with Cox regression. Results—Compared with exposed cohort cows, the hazard ratios for unexposed cohort cows having positive culture results, having positive ELISA results, and developing CJD were 0.12, 0.03, and 0.001, respectively, and those ratios increased by 2%, 6%, and 17%, respectively, for each month spent in an MAP-infected herd. Conclusions and Clinical Relevance—Delayed exposure of cows to MAP resulted in lower incidences of positive culture and ELISA results and CJD in those cows, compared with incidences of cows exposed to MAP since birth. The hazard of testing positive for MAP or developing CJD increased with time, regardless of cohort.

Objective: To evaluate the growth kinetics of a strain of Bifidobacterium pseudocatenulatum (BP) on 4 oligo- or polysaccharides and the effect of feeding a selected probiotic-prebiotic combination on intestinal microbiota in cats. Animals: 10 healthy adult cats. Procedures: Growth kinetics of a strain of cat-origin BP (BP-B82) on fructo-oligosaccharides, galacto-oligosaccharides (GOS), lactitol, or pectins was determined, and the combination of GOS and BP-B82 was selected. Cats received supplemental once-daily feeding of 1% GOS–BP-B82 (10(10) CFUs/d) for 15 days; fecal samples were collected for analysis the day before (day 0) and 1 and 10 days after the feeding period (day 16 and 25, respectively). Results: Compared with the prefeeding value, mean fecal ammonia concentration was significantly lower on days 16 and 25 (288 and 281 μmol/g of fecal dry matter [fDM], respectively, vs 353 μmol/g of fDM); fecal acetic acid concentration was higher on day 16 (171 μmol/g of fDM vs 132 μmol/g of fDM). On day 16, fecal concentrations of lactic, n-valeric, and isovaleric acids (3.61, 1.52, and 3.55 μmol/g of fDM, respectively) were significantly lower than on days 0 (5.08, 18.4, and 6.48 μmol/g of fDM, respectively) and 25 (4.24, 17.3, and 6.17 μmol/g of fDM, respectively). A significant increase in fecal bifidobacteria content was observed on days 16 and 25 (7.98 and 7.52 log10 CFUs/g of fDM, respectively), compared with the prefeeding value (5.63 log10 CFUs/g of fDM). Conclusions and Clinical Relevance: Results suggested that feeding 1% GOS–BP-B82 combination had some positive effects on the intestinal microbiota in cats.

Lawsonia intracellularis infection causes proliferative enteropathy (PE) in many mammalian species, with porcine and equine proliferative enteropathy (PPE and EPE) known worldwide. Hamsters are a well-published animal model for PPE infection studies in pigs. There is no laboratory animal model for EPE infection studies and it is not known whether there is species-specificity for equine or porcine isolates of L. intracellularis in animal models. The objective of this study was to determine whether it is possible to generate typical EPE lesions in hamsters after inoculation with an equine strain of L. intracellularis (EPE strain) and whether it is comparatively possible to generate PPE lesions in rabbits after inoculation with a porcine strain of L. intracellularis (PPE strain). In 2 separate trials, 4-week-old and 3-week-old weanling golden Syrian hamsters were challenged with EPE strains and compared to uninfected (both trials) and PPE-infected controls (Trial 2 only). Concurrently, 6 female New Zealand white juvenile rabbits were infected with PPE strain and observed concomitantly to 8 similar rabbits infected with EPE strain for a different experiment. Hamsters and rabbits were observed for 21 to 24 days post-infection (DPI), depending on the experiment. Neither infected species developed clinical signs. The presence of disease was assessed with diagnostic techniques classically used for pigs and horses: immune-peroxidase monolayer assay on sera; quantitative polymerase chain reaction (qPCR) detection of molecular DNA in feces; and hematoxylin and eosin (H&E) stain and immunohistochemistry (IHC) on intestinal tissues. Our results showed that EPE-challenged hamsters do not develop infection when compared with PPE controls (IHC, P = 0.009; qPCR, P = 0.0003). Conversely, PPE-challenged rabbits do not develop typical intestinal lesions in comparison to EPE-challenged rabbits, with serological response at 14 DPI being significantly lower (P = 0.0023). In conclusion, PPE and EPE strains appear to have different host-specificities for hamsters and rabbits, respectively.